Defiberizing redwood-bark



U. S. McM|LLAN.Q-

nEHBEmzlNG REDwooD BARK.

Patented J une 22, 1920. l 2 SHEETS-SHEET `2.

wm A M 45 act upon the bark longitudinally of the UNITED i sTATEs PATENToEFlcE.

UEL S. MQMILLAN, OF SAN FRANCISCO, CALIFORNIA,

DEFIBERIZIN G REDWOOD-BARK.

Specification of Letters Patent. Patented June 22 1920 Application filedNovember 26, 19.19. SerialiNo. 340,772.

T o ZZ wlw/1L t may concern.'

Be it known that I, Uni. S. MeMiLLAN, a citizen of the United States,residing at San Francisco, in the`county of San F'rancisco `and State ofialifornia, have invented new r and useful Improvements in .DefiberizingRedwood-Bark, of which the following is a specification.

T his invention relates to the defiberizing of the bark of Californiaredwood.y .California redwood orSeguoza Semper-virent is indigenous tothe Pacifieslope. This bark is sui generis and is characterized by thepresence of long loose fibers in layers alternating with., layers ofbast-fiber. The long loose fiber, if properly preserved indefiberization, is admirably suited for paper pulp making, as amplyproven by many laboratory tests conducted by the forestry department ofthe United States Government.

In the present invention, I provide a method and apparatus fordefberizing redwood bark in a manner to' remove the fiber without at thesame time crushin and 2b grinding it into small particles. n the presentform of my invention, this is accomplished by the use of a movablecombing i element, preferably in the form of a wire brush which actsuponthe bark longitudi- 30j nally of the grain or fiber.

In the accompanying drawings:

Figure 1 shows a vertical elevation, partly in section, of a suitableform of apparatus for practising my method.

Fig. 2 shows an enlarged or exaggerated -view'in perspective of a'pieceof redwood bark, the.. edge or thickness of the bark `appearing at thefront of the view.

Fig.' 3 `shows a diagram of a modified element.

Fig. 4 shows t e application of my invention to the bark as'contain'edon a log, the log being assed beneath the combing eleli element issuitably mounted to show in F ig. 1 a conventional apparatus forperforming my method. In a general way this apparatus comprises acombineP element 10, in the form of a rotary wire brus powerdriven atthe desired speed, a guide member 11 for feeding the ,bark .to the brush.is

a manner to present the bark so that the brush will act longitudinallyof the fiber or grain-of the bark. A receptacle or conveyer 12 1spositioned beneath the brush to catch the defiberized material.

In Fig. 2 I show an enlarged vertical cross section of a kslab ofredwood bark wherein A indicates in exaggerated form the layers ofbast-fiber, and B the intermediate layers of long loose fiber. Thebast-fiber is hard and brittle. Therefore, I may feed the bark to thecombing element in such a way that the wire brush will act on thelongitudinal edge face of the bark rather than the longitudinal sideface, since in so doing the wires of the brush will get in between thebast-fiber layers and tear away the other fibers without breaking upland crushing the long fiber. I may also feed the bark so that the brushwill act on the side face longitudinally of the fibers, as when workingon a log. The important requisite is that the brush acts longitudinallyof the fibers at all times.` The long fiber will not thereby be groundup or broken into small particles land will thus be better suited forpaper pulp USBS- In Figf' I show a modified form of combingelementcomprising an endless belt 13,

on the outer` surface of which are arranged 10 may be mounted on a frame15, beneath which the log is conveyed by suitable means 16. Thereby thebark is removed from the log and at the same time defiberized. Thismethod of employing my invention saves the expense and labor ofstripping the bark from the log.

Heretofore the bark of redwood has been peeled off in the woods or atthe mills, inasmuch as the vlogs cannot be successfully sawed with thebark thereon. This is because the stringy fiber of the bark quicklydulls the teeth of the saw and being drawn into the pathway of the sawoften causes the saw to spring out of its course. The bark, therefore,is generally pulled from the log by hand means and thereafter burned aswaste. Therefore, by my invention I not onl eliminate the expense andlabor .of peeling the bark from the logs but convert this bark into a4valuable by-product.

By the foregoing described'invention, the (leberizing of redwood bark ismade comparatively simple and easy Lind the long fiber is not crushed orbroken up, and hence it will produce a better andl stronger peper.

IVhile I have shown a carrier 16 for bringing the l'og into positionbeneath the brush, it will be understood that the brush muy be appliedto the log as the' latter passes through a fiume on its way to the mill.The bark need not necessarily be dry, and, in fact, I find that dampenedbark is more easy to. lefiberize than dry berk.`

Various changes in the construction und arrangement of the several partsmay be employed Without departing from the spirit of my invention asdisclosed in the appended elaims.

Having thus described my'invention, what I claim und desire to secure byLetters Pntent is:

l. The process of defiberizing Wood whielf consists in subjecting thesolid wood to zt yielding combing action in line with the length of theibers of the sume.

2. A wood defiberizing machine comprising a hopper having front and rearwalls, the rear wall extending below the Jfront tvull and a rotary Wirebrush detiberizer, the periphery of which extends into seid hopper belowsaid upper Wall und backwzu'dly udjucent the rear wall above the bottomof said rear Wall.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing Witnesses.

UEL S. MCMILLAN. Witnesses WM. HEALEY, M. E. EWING.`I t

